Pump and air separator unit



July 8, 1947. wtu. DE LANCE! 2,423,439

POM? AND AIR SEPARATOR mu'r Filed lay 16, 1944 s sneaks-sheet 1 ATTORNEY.

July 8,1947. w. was LANCEY I 2,423,439

PUIIP AND AIR SEPARATOR UNIT Film; lay 16. 1944 5 sheets-skeet 3 r 4 z 4 fi g 7 g 4/ I 4 7.9 V g m g 7/ 70 4 g l ,d/ 15 5 z ATTORNEY.

July 8, 1947. v w. H. DE LANCE! PUMP AND AIR SEPARA'LTC'R UNIT Filed May'lS, 1944 5 Sheets-Sheei M ,1; if

; MAQOW Patented July 8, 1947 PUMP AND AIR SEPARATOR UNIT Warren H. De Lancey, Springfield, Mass., as-

signor to Gilbert 8t. Barker Manufacturing Company, West Springfield, Mass., a corporation of Massachusetts Application May 16, 1944, Serial No. 535,841

18 Claims. 1

This invention relates to improvements in pump and air separator units such as are particularly adapted for use with gasoline dispensing apparatus.

The invention has for an object to provide a combined pump and air separator unit in which the pump is located in the liquid recovery chamber of the separator, such chamber serving also as a priming chamber, whereby the pump can quickly prime itself with a low lift of the liquid from said chamber.

The invention also has for an 'object the pro- ,vision of a pump of the type having rotary elements mounted in a casing between end plates and located in the liquid recovery chamber of the separator, the construction being characterized in that the pump casing and its end plates are in direct abutmentbecause of the omission cf the usual gaskets and by a close running fit between the end plates and the end faces of the rotary elements of the pump, any leakage from the pump being received in the liquid recovery chamber 01 the separator.

Another-object of the invention is to provide in a pump and air separator unit an improved control of the return flow from the liquid recovery chamber to the suction side of the pump, characterized by steadiness of discharge under widely varying conditions and by ease of valve action by a small actuating float. v

' The invention has for another object to provide in a combined pump and separator unit, improved by-pass control, characterized by a two stage ac tion of the valve, which eliminates chattering, nd by an arrangement, whereby the liquid as lt enters the by-pass reacts on the valve with a pressure to offset the increase in pressure of the valve spring, thereby enabling the by-pass to be held open at relatively low pressure.

The invention has for an object the provision of an improved pump and air-separating structure which is relatively inexpensive to manufacture, quiet and efflcientin operation and calcu-. oed to have a long life wthout requiring service irg.

These objects-will best be understood as the detai ed description proceeds and they will be po ted out in the appended claims.

The invention will be disclosed with reference to the accompanying drawings, in which- Figs. 1 and 2 are top plan and side elevational views. respectively, of .a combined pump andseparatcr unit embodying the invention;

Fig. 3 is a sectional elevational view thereof taken on the line 3-4 of Fig. 2;

of F18. 3;

Fig. 5 is a fragmentary sectional view showing the by-pass valve;

Fig. 6 is a cross sectional view taken 6-& of Fig. 5;

Fig. 7 is a sectional view taken on the line '|-'-'I of Fig. 3;

Fig. 8 is a large-scale, fragmentary, sectional view taken on the line 8-8 of Fig. 7; s

Fig. 9 is a sectional plan view taken on the line 9-9 of Fig. 8;

Fig. 10 is a sectional elevational view takenon the line i0l0 of Fig. 1;

Fig. 11 is a sectional elevational view taken on the line ll-ll of Fig. 10;

Fig. 12 is a sectional view taken on the line i2-l2 of Fig. 11;

Fig. 13 is a sectional plan view taken on'the line i3-l3 of Fig. 10; and

Fig. 14 is a sectional plan line I4-i4 of Fig. 11. 1 I

Referring to these drawings; the invention atfords a pump for liquid, a separator for air and gases, a filter, a bypass around the pump, a presrure-relief valve controlling the by-pass, and a float-actuated valve controlling return of liquid from the separator to the pump, together with the necessary passages leading to these several parts, all rovided in a single casing 0, shown generally in Figs. 1 and 2.

The casing (2 includes a body portion l5, and a on the line view taken on the cover is extending completely across one side,

whereby to connect with the inlet of a meter,

shown in part at M. On the front and back walls of member iii are faced-oh. 'bosses 24 with tapped holes therein 2% (Fig. 12), whereby to connect the unit to a suitable support, such for example as the frame or the housing of a gasoline dispensing apparatus.

The housing C is subdivided by a vertical partition wall 25 (Figs. 3 and i i) into a primary airseparating chamber 27 and a secondary separating chamber 28. The secondary chamber is also called a liquid recovery chamber, These chambers are arranged side by side at the same level. Near the lower part of the chamber 27 is an air-separating filter 29 of annular form.

This filter may be of any kind suitable for the purpose of preventing the passage through it of bubbles of air or gas. It may, for example, be of cotton thread wound upon a wire screen core as indicated. This filter will also prevent the passage of water and it will prevent dirt and grit from passing into the meter. The filter is held in place by two annular rings 88 and 8| formed on the partition 28 and a cover plate 80, respectitvely, and engaging the ends of the filter unit. The circular plate 30 is held to the body l5, with a gasket 8| clamped therebetween, by a series of cap screws 82. This cover closes, liquid tight, an opening in a side wall of body l5, through which opening the filter 28 may be inserted or removed. Fluids, liquid and/or gaseous, enter the primary separator chamber by spilling over a dam 33 in the upper part thereof. The liquid only will pass through the filter 28 into the interior thereof. The air and gases remain outside the filter. Airfree liquid, passing through the filter, is received in a coaxial cylindrical recess 84, forming one terminal of an outlet conduit 85 extending vertically upward and having the outlet 2| adapted for connection to the meter M. Both the recess 34 and the conduit 35 are formed in the partition 26 described.

The separator chamber 21. has a constantly open vent passage of small cross sectional area as compared with the inlet and outlet passages for liquid. This vent is shown at 88 in Figs. 1 and 3. It is formed in the top wall of the separator chamber 21 and opens into a recess 31 formed in flange 22. The base flange of meter M rests on flange 22 and closes the top of the recess in liquid-tight fashion. The only outlet from this recess is by way of a hole 38 which is formed in the top wall of body l4 and which opens into the secondary chamber 28.

The pump, by means of which fiuids are drawn up from a low level supply tank through suction pipe 20, is designated generally by reference letter P. This pump (Figs. 3 and 7), is located in the liquid recovery chamber 28, near the upper part thereof, and is carried by the cover I8. A faced-oil portion 89 of the inner wall of this cover forms one end wall of the pump housing. Inlet and outlet ports 48 and 4|, respectively,

are formed in this portion 38 and are connectedby upwardly-diverging, radial passages 42 and 43, to the upper corners of the cover, terminating with horizontal holes 44 and 45. These holes 44 and 45 open into the faced-oil marginal portion 48 of the cover that is clamped against the gasket l1. The pump has a shell 41 and an inner end wall 48 which are clamped together and to the face 38 of the cover by a series of cap screws 48. The shell is bored out to closely fit the finished outer peripheral wall of an annular gear 50. Within the annular gear is a gear fixed to one end of a driving shaft 52, which is mounted in suitable bearings, one in cover 48 and one in cover I 8 (Fig. 3), and is driven from any suitable source of power. The end faces of gears 58 and 5| closely fit the adjacent inner faces of cover l8 and end wall 48. Such fitting may be secured with close accuracy because of the absence of gaskets between the shell 41 and the end walls i8 and 48. The gaskets can safely be omitted because any leakage will pass into the lower part of the chamber 28, from which liquid is returned to the suction side of pump P in a manner to be later described.

The inlet and outlet holes 44 and 45 register with similar holes 53 and 54 one in each upper corner of the body member I! (Figs. wand 13). The outlet 54 opens into a horizontal passage 55 formed in the upper part of the separator chamber 28 and extending across the same. Pasone side wail'of body i5 (Figs. 1

sage 55 communicates with a trough 58 which traverses the separator chamber 21 and communicates therewith by the opening 51 above the described dam '33, which is a top side edge of the trough 58. The inlet hole 53 opens into a horizontal passage 58 which extends completely across the upper part of the body I4. Intermediate the ends of this passage 58 is a seat 59 which receives and closely fits the inner end of a cylindrical screen 60. This screen is fixed to a nut 6|, threaded into an opening formed in body I4 coaxially of passage 58. The arrangement is such that liquid supplied to the annular chamber 62 outside the screen cannot reach the left hand portion of passage 58, shown in Fig. 11, except by passing radially through the peripheral portion of the screen and into its interior, whence it can flow freely in an axial direction toward hole 53. A passage 83 extends from chamber 62 along and 14) and at a slight inclination (Figs. 11 and 14) to a small chamber 64 near the bottom wall of the body where it communicates with suction pipe 20.

The secondary separator chamber 28 has a vent in its upper end consisting of a. pipe 65 threaded into the top of cover 18 and leading upwardly to a suitable height.

The separator chambers 21 and 28 are provided with drain openings normally closed by plugs 66 and 61, respectively (see Fig. 14). Through these openings any sediment or any water that may collect in the chambers may be drained off.

Means are provided for returning to the pump P excess liquid which accumulates in the secondary separator 28. Such means include a vettical passage 68, formed in cover l8 alon one side edge thereof and extending upwardly from the lower edge of the cover and opening into the described inlet passage 42. The lower end of passage 68 is closed by a plug 89. Near the lower end of this passage is a port 18 (Fig. 4). Secured to the wall of passage 88, as by screws 1!, is a valve seat 12, which is preferably made of chromium-plated metal, providing a smooth, noncorrodible face to slidably receive the valve 13. This valve is preferably made of carbon and its valve-engaging face is lapped, providing a smooth, hard, glass-like surface which slides easily on the seat and is also non-corrodible. A port 14 is provided in seat 12, communicating with the port 10. Secured to the side edges of seat 12 is an approximately U-shaped metal case 15 which serves to guide the valve in its vertical path of reciprocation. A float 18 in chamber 28 has a stem 11 which passes through the sides of case 15 and has its free end pivotally connected to and between a pair of ears 18 on the case. Projecting from one side of stem 11 is a projection 19 which extends into a hole 88 in the valve. Springs 8|, each fitting at one end into a socket in valve 14 and at the other end over a button on the interior of case 15, serve to press the valve against its seat. The float lifts the valve as the liquid risesin chamber 28 above a, predetermined level and its lower edge will be carriedupwardly to uncover port 14. Liquid can then enter passage 68 and be drawn up by pump P into its suction port and ejected into the separator chainber 21. Due to the extremely low coefiicient of friction between the mating faces of the valve and Seat, the valve may easily be moved and by a much smaller float than has heretofore been customary. Also contributing to this result is the use of a slide valve, instead of the customary P PDE valve, and the arrangement of the slide valve vertically as shown, so that it does not have to be lifted against the entire liquid head in chamber 28 but instead is dragged over a smooth surface to which it is held frictionally and, as stated, the coefficient of friction between the mating surfaces is very low.

The pump P isprovided with a by-pass and a for the by-pass valve 84, which is formed on one end of a sleeve 85, having vanes 85' (Fig. 6), which slidably fit passage 83. On the other end of sleeve 85 is a flange 86 which functions as an annular piston, exposed at all times to the pressure of the liquid in the outlet of pump P. A nut 81 closes the outer end of passage 83. A breather hole 83 connects the outer end of hole 83 to the air space of chamber 28. A spring 88, one end of which fits in a socket in nut 81 and the other end of which fits in sleeve 85, tends to hold valve 84 closed.

This valve has a cylindrical plug 89 which closely fits in the outlet end of by-pass 82. The purpose of this .plug is to avoid chattering of the valve. Therewill be substantially no flow into passage 82 until the plug has been completely withdrawn therefrom and when this occurs, the valve 84 will have been moved so far from its seat that chattering will not occur. The ordinarycause of chattering is the pressure drop which ensues on the initial opening of'the valve, and which allows the spring to close the valve suddenly and impinge on itsseat. This is followed by a rise in pressure, whereupon the valve opens slightly again only to be followedby another closing as the pressure drops. The action described is repeated over and over again, causing a chattering due to the repeated impingements of the valve upon its seat.

Beyond the plug 88 is a projection 88 forming a guide. The surface of this guide is a concave surface of revolution (see Fig. 5). It is formed by revolving an arc of a circle of substantially ninety degrees about the axis of the valve, which axis parallels one of the tangents of the arc. This guiding surface serves to direct the liquid which, when plug 88 is withdrawn from the end of passage 82, enters the latter in all radial directions, into a longitudinal, evenly-distributed stream. Also, the reaction pressure of the liquid, when leaving the curved surface is utilized for the purpose of aiding the valve-opening movement. The liquid, leaving the guide, reacts on the same with an axially outward thrust in opposition to the force .exerted by spring 88, much as liquid leaving a turbineblade reacts on the same with a forward thrust in the direction of rotation. As valve 84 opens, the spring being compressed by the valve opening movement, exerts an increased force on the valve in a direction tending to close it. The reaction thrust described offsets the increase in spring pressure and it may and preferably does offset the force due to spring pressure to an even greater extent so that the valve, once opened, may be held open by a. somewhat lower pressure than that required t6 open it.

The pump shaft 52 passes out through cover l6 for connection to any suitable driving motor. A suitable seal 82 is provided in the cover to prevent liquid from passing along the shaft out of the cover and such liquid as does reach the inner part of the chamber 83 adjacent the seal, is drained off into the chamber 28 by way of a passage 8|.

The pumping and separator unit is adapted for use in a gasoline dispenser, such for example, as that disclosed in my prior Patent No. 2,280,287, dated April 21, 1942. The unit may be substituted for the one shown in said patent, being located between and connected to the suction pipe and the meter. The pump may be driven by an electric motor coupled directly or indirectly to shaft 52 and controlled as indicated in said patent.

In operation, when the apparatus is first installed, the pump will be driven until all the air has been expelled from the suction line and most of chamber 21, such air passing out of the chamber 21 through passages 36, 31, 38 and vent pipe 65. After this has been done, continued operation-of the pump with the hose nozzle open will force liquid out of conduit 35, meter M and the discharge line of the meter, driving ahead of it the air. When liquid flows out of the hose nozzle, the apparatus will have been completely primed and ready for use in the normal way.

The normal operation is substantially the same as usual. Liquid entering the separator near the top is slowed down in velocity to help release any entrained air. The filter 28 definitely prevents the passage of air to the meter. Therefore, the air has to rise to the top of chamber 21 and escape through the passages 36, 31 and 38 to the liquid recovery chamber 28. If air is' entrained in the liquid, there will be a stream of mixed liquid and air passing into chamber 28. Separation of air and liquid occursunder atmospheric pressure in chamber 28. The air passes out by vent pipe 65. The separated liquid is collected in the bottom of chamber 28 and returned through passage 68 to the suction side of the pump- On each cessation of pumping, the pressure in the separator drops to atmospheric because of the vent 36, 31, 38 to chamber 28 which in turn is vented to the atmosphere by pipe 65. The chamber 21, which has been filled with liquid, now drains back to the level of the top of dam 33. Liquid will flow back in passage 56 and ports 54 and 45 to the pump outlet port 43 and through the pump to the inlet port 42 and thence down passage 68 and the then open valve 12 into the base, of the liquid rezovel'ychamber 28. Liquid in passage 58 will also drain into passage 68. The liquid in the passages 56 and 58 can drain of! to the level of the lowest parts of the ports 44 and 45. The liquid in the outlet passage 4| and in the inlet passage 48 can drain into pas--.

sage 68 down to the level of the top of such passage. The pump may even drain down to the level of the top of the vent hole 83' past the piston 86 of the by-pass valve 84. The passage 68 will drain until the level therein equals that in chamber 28. And, in time, due to the lack of gaskets in the pump, thelatter might entirely empty. All the drainage goes into chamber 28 and the liquid therein may rise to a level close to the lower end of the pump housing. This gives 7 a supply of liquid for priming the pump on its next succeeding operation.

It was stated that valve 12 is open to allow the same rate that it is forced into the top of the liquid recovery chamber through the constantly open vent 36. Thus, the valve 12 would normally be partly open, as above stated, at the beginning of the drain back movement. The valve 12 will then rise as the draining continues, and when the pump is again started it will drop as the liquid is drawn into the pump and it will close if liquid reaches the predetermined level in chamber 28 but it will later open again when liquidagain is forced into the chamber 28.

In theevent of a leaky foot valve in the suction pipe 20 the latter may become wholly or partially empty and require priming. Priming may also be necessary because of vaporization of the volatile liquid in the case of a long suction line lying close to the ground and exposed to intense heat. The pump,,being of the positive type, will, of course, evacuate the air and gases, forcing them out of the top of chamber 21 through passages 36, 31 and 38 into chamber 28 and thence out through vent 55.

In any case, the pump will be quickly and easily primed by the liquid which accumulates in chamber 28. Only a lift of a few inches is necessary to draw liquid into the pump and almost in an instant, the pump is filled with liquid and primed. In the ordinary installation heretofore, a leaky foot valve could cause draining of the pump and of the whole suction line and before the pump could be primed, it was necessary to scavenge the suction line. A lift of many feet instead of a few inches was necessary to fill the pump with liquid. The location of the pump in the liquid recovery chamber above the normal liquid level therein not only enables easy priming but it enables the parts of the pump to be fitted together in direct abutment without intervening gaskets so that tolerances much smaller than usual may be used, and a closer fit obtained between the end faces of the rotors 50 and SI of the pump and the end plates 44 and 48. A better and more efllcient pump results. No trouble can come from the omission of the gaskets because any leakage goes into chamber 28 and is collected and returned to the pump. Any leakage from chamber 28 along shaft 52 may be drained into chamber 28, as by the passage 9! in cover l6.

Whenever the hose nozzle valve of the dispensing apparatus is closed before the pump motor is stopped, the pressure rise in the system opens the by-pass valve and allows liquid to circulate from the outlet to the inlet port of the pump in an exceedingly short path. The work of the pump is then reduced to that necessary to circulate the liquid in the by-pass. No substantial lift is involved but pressure must be maintained to hold the by-pass valve open. This pressure may be reduced below the pressure initially needed to open the valve because of the reaction of the liquid on the end 90 of the valve in a direction opposite to that of the force of spring 88. The control of the by-pass is also improved by what may be called the two-stage action of the valve. The initial stage includes the movement of the valve under the action of the outlet pressure on the annular area of piston 86. The valve 84 is thereby moved away from its seat a substantial distance before liquid can enter the by-pass. The second stage occurs on the removal of the plug ortion 89 of the valve from the inlet end of the by-pass. An additional force is then available due to the reaction of the liquid on the end of the valve. This additional force more than oil'sets the increase in force of spring 88 and enables the valve to be held open by a force less than that required to open it. The arrangement also avoids chattering and enables a smooth, steady valve action.

The control of the return flow to the pump is also materially improved. The use of a slide valve as against the usual poppet valve, and the provision of mating valve surfaces with an extremely low coefflcient of friction enable the valve to be moved easily by a very small float. The construction is compact. The control is improved because of the steadiness of the return flow. The valve does not bob back and forth during 8, normal dispensing operation but seeks a position and remains there. The operation of the valve is not materially affected by variations of suction lift. The valve is not held to its seat by the whole force of hydraulic pressure, as in the case of a poppet valve, and therefore variations in pressure do not affect the operation of the valve to any serious extent.

The construction is relatively simple and inexpensive to manufacture. The entire pump may be made of molded parts, requiring little or no machining other than the tapping of holes for the retaining screws. The by-pass valve may be a die casting, requiring no machinery. Simple drilling forms the by-pass and its cylinder. A common plug closes the outer end of such cylinder. The

return valve mechanism is likewise simple and inexpensive to make. The finishing of the body casting i5 involves merely the facing of the flat surfaces for the covers i 6 and 30 and of flange 22, together with the drilling and tapping of the necessary holes for the retaining screws. The cover l8 also requires facing for the gasket I1 and for the pump body, together with a few drilling and tapping operations. Nothing of a complicated or expensive nature is necessary to finish the parts or to assemble them.

The invention thus provides an improved pump and separator unit for gasoline dispensers characterized by simplicity of construction, low cost of manufacture, improved and more quiet operation, including better control of the by-pass and better control of the return flow from the liquid recovery chamber to the pump.

I claim:

1. An apparatus of the class described, having an air-separating chamber with an inlet delivering into the upper part thereof, an outlet for airfree liquid in the lower part thereof and a vent passage for fluid near the top thereof; and a liquid-recovery chamber connected to receive fluid from said vent passage and having a vent for air in the upper part thereof; a pump for forcing fluids into the inlet of the separating chamber, said pump being located in the liquid-recovery chamber, a suction conduit for the pump, a return conduit connecting the lower part of the liquid-recovery chamber to the suction conduit,

and a valve controlling said return conduit and opening and closing it in response to rise and fall of the liquid in the liquid-recovery chamber above and to a predetermined level, respectively.

2. An apparatus of the class described, having an air-separating chamber with an inlet thereto near the top thereof and an outlet for air-free liquid nearthe bottom thereof, a liquid-recovery chamber vented to the atmosphere, a vent passage connecting the upper parts of the separating and liquid-recovery chambers, a pump for forcing fluids into the inlet of said separator and out of said outlet, a suction conduit for the pump, a return conduit from the lower part of the liquidrecovery chamber to said suction conduit. a valve controlling the outflow of liquid in the liquidrecovery chamber above a predetermined level for opening said valve, said pump being located in the liquid-recovery chamber above said level.

3. An apparatus of the class described, comprising a casing having an air-separating chamber, a vented liquid-recovery chamber, an inlet and an outlet for the separating chamber respectively near the top and near the bottom thereof, and a, vent passage interconnecting the chambers near their upper ends; a cover for and forming one side wall of the liquid-recovery chamber and removably secured to said casing, and a. pump mounted on said cover and located in the upper portion of the liquid-recovery chamber, said cover having inlet and outlet ports for the pump and inlet and outlet passages, the pump outlet passage connecting with the separator inlet passage when the cover is in place.

4. An apparatus or the class described, comprising a casing having an air-separating chamber, a vented liquid-recovery chamber, an inlet and outlet for the separating chamber respectively near the top and near the bottom thereof, a vent passage interconnecting the chambers near their upper ends, and a suction passage; a cover for and forming one side wall of the liquid-recovery chamber and removably secured to said casing, and a pump mounted on said cover and located in the upper portion of the recovery chamber, said cover having inlet and outlet ports for the pump and inlet and outlet passages for connection respectively to said suction passage and the separator inlet passage when the cover is in place.

5. An apparatus or the class described, comprising a casing having an air-separating chamber, a vented liquid-recovery chamber, an inlet and outlet for the separating chamber respectively near the top and near the bottom thereof, and a vent passage interconnecting the chambers near their upper ends; a cover for and forming one side wall of the liquid-recovery chamber and removably secured to said casing, a pump mounted on said cover and located in the upper portion of the recovery chamber, said cover having inlet and outlet ports for the pump and inlet and outlet passages, the pump outlet passage connecting with the separator inlet passage when the cover is in place, said cover having a passage from the inlet port or the pump opening into the lower end of the separator, and a float-actuated valve in the liquid-recovery chamber to control the return passage.

6. An apparatus of the class described, comprising a casing having an air-separating chamber, a vented liquid-recovery chamber, an inlet "Zand outlet for the separating chamber respectively near the top and near the bottom thereof, and a vent passageinterconnecting the chamber, a vented liquid-recovery bers near their upper ends; a cover for and forming one side wall of the liquid-recovery chamber and removably secured to said casing, a pump mounted on said cover and located in the upper portion of the recovery chamber, said cover having inlet and outlet ports for the pump and inlet and outlet passages, the pump outlet passage connecting with the separator inlet passage when the cover is in place, said cover having a return flow passage from the bottom of the liquidrecovery chamber to the inlet passage of the pump, a valve for controlling said return flow passage and mounted on said cover, and a float eonnectedto the valve for actuating the same in response to variations in the liquid level in the recovery chamber.

7. An apparatus of the class described, comprising a casing having an air-separating chamchamber, an inlet and outlet for the separating chamber respectively near the top and near the bottom thereof, and a vent passage interconnecting the chambers near their upper ends; a cover for and forming one side wall of the liquid recovery chamber and removably secured to said casing, a pump mounted on said cover and located in the upper portion of the recovery chamber, said cover having inlet and outlet ports for the pump and inlet and outlet passages, said cover having a short bypass between the pump inlet and outlet ports, and

prising a casing having an air-separating chamber, a vented liquid-recovery chamber, an inlet and outlet for the separating chamber respectively near the top and near the bottom thereof, and a vent passage interconnecting the chambers near their upper ends; a cover for and forming one side wall of the liquid-recovery chamber and removably secured to said casing, a pump mounted on said cover and located in the upper portion of the recovery chamber, said cover having inlet and outlet ports for the pump and inlet and outlet passages, the pump outlet passage connecting with the separator inlet passage when the cover is in place, said cover having a passage for connecting the lower end of the liquid-recovery chamber to the inlet passage of the pump, including a port in a vertical wall for connecting the passage and liquid-recovery chamber, a slide valve reciprocating vertically on said wall for opening and closing said port, and a float in the liquid-recovery chamber for actuating the valve.

9. An apparatus of the class described, comprising a casing having an air-separating cham-- ber, a vented liquid-recovery chamber, an inlet and outlet for the separating chamber respectively near the top and near the bottom thereof, anda vent passage between the chambers near their upper ends; a cover for and forming one side wall or the liquid-recovery chamber and removably secured to said casing, said cover having 8. An apparatus of the class described, com-v 1.1 7 together in direct abutment one with another, whereby the end faces of the rotary elements may have a close and accurate running lit with said finished faces.

10. An air separator, comprising, a box-like housing having a partition dividing it into an air-separating chamber and a liquid-recovery chamber, said chambers having openings one on each of two opposite sides of the housing that parallel said partition, covers one for each opening, said partition having a conduit therein forming an outlet for air-free liquid from the separator chamber, said conduit having one terminal opening located opposite the opening in the side wall of the separating chamber, an air-separating filter mounted between the partition and the cover for the opening in the separating chamber and encompassing said terminal opening of the outlet conduit, said housing having an inlet for fluids opening into the upper part of the separating chamber and a vent passage interconnecting said chambers near their upper ends, a vent for the liquid-recovery chamber, and float-controlled means in the latter chamber for enabling the discharge of liquid therefrom after it reaches a predetermined level.

11. An air separator, comprising, a box-like housing having a partition dividing it into an airseparating chamber and a liquid-recovery chamber, said chambers having openings one on each of two opposite sides of the housing that parallel said partition, covers one for each opening, said partition having a conduit therein forming an outlet for air-free liquid from the separating chamber, said conduit having one terminal opening located opposite the opening in the side wall of the separating chamber, an air-separating fllter mounted between the partition and the cover for the opening in the separating chamber and encompassing said terminal opening, said housing having an inlet for fluids opening into the upper part of the separating chamber and a vent passage interconnecting said chambers near their upper ends, and a vent for the liquid-recovery chamber, a pump carried by the other cover; said last-named cover having a suction passage, 9. discharge passage communicating with said liquid inlet, and a return passage interconnecting the suction passage and the lower part of the liquidrecovery chamber; a valve controlling the return passage, and a float in the liquid-recovery chamber for actuating said valve.

12. An air separator, comprising, a box-like housing having a vertical partition dividing it into air-separating and liquid-recovery chambers, each chamber having an opening in the side wall opposite said partition, 9. cover for each opening, a pump located in the liquid-recovery chamber and carried by the cover therefor, suction and discharge conduits in said housing for said pump, the discharge conduit opening into the upper part of the separating chamber, a conduit of restricted area interconnecting the chambers near their upper ends, a vent conduit for the liquid-recovery chamber, a return conduit from the lower part of the latter to the suction conduit of the pump, a valve controlling the return conduit, and a float in the liquid-recovery chamber for controlling said valve.

13. An air separator, comprising, a box-like housing having a vertical partition dividing it into air-separating and liquid-recovery chainbers, each chamber having an opening in the side wall oppo he said partition, a cover for each opening, a pump located in the liquid-recovery chamber and carried by the cover therefor; said cover having inlet and outlet ports for the pump, and inlet and outlet passages leading upwardly from the ports toward the upper corners of the cover and terminating with openings through the inner face of the cover; the housing having inlet and outlet passages terminating at one end with openings to connect with said cover openings, the outlet passage in the housing terminating at its other end with an opening into the upper part of the separating chamber. the inlet passage in the housing terminating with a port for connection to a suction pipe, the housing having an out let from the lower part of the separating cham ber for air-free liquid and a vent passage interconnecting said chambers near their upper ends, and a vent for the liquid-recovery chamber, said cover having a return conduit opening at its lower end into the lower part of the liquid-recovery chamber and at its upper end into the inlet passage of the pump, and a float-operated valve in the liquid-recovery chamber for controlling said return conduit.

14. In an air separator, having an air-separating chamber and a vented liquid-recovery chamber with a vent passage interconnecting them near their upper ends, inlet and outlet conduits leading respectively to the upper part and from the lower part of the separating chamber, a corrduit for carrying away excess liquids from the liquid-recovery chamber and terminating with a port opening through a vertical wall near the base of the liquid-recovery chamber, said wall having a finished vertical face forming a valve seat, a slide valve vertically reciprocable on said seat to uncover and cover said port as the liquid respectively rises and falls in the liquid-recovery chamber, and a float in the latter to reciprocate said valve.

15. In an air separator, having an air separating chamber and a vented liquid-recovery chamber with a vent passage interconnecting them near their upper ends, inlet and outlet conduits leading respectively to the upper part and irom the lower part of the separating chamber, a conduit for carrying away excess liquids from the liquid-recovery chamber and terminating with a port opening through a vertical wall near the base of the liquid-recovery chamber, said wall having a finished vertical face forming a valve seat. a slide valve vertically reciprocable on said seat to uncover and cover said port as the liquid rises and falls in the liquid-recovery chamber, that part. of said valve which engages said seat made of carbon and having its seat-engaging face lapped to glass-like smoothness.

16. In an air separator, having an air-separating chamber and a vented liquid-recovery cham ber with a vent passage interconnecting them near their upper ends, inlet and outlet conduits leading respectively to the upper part and from the lower part of the separating chamber, a conduit for carrying away excess liquids from the liquid-recovery chamber and terminating with a port opening through a vertical wall near the base of the liquid recovery chamber, said wall having a, finished vertical face forming a valve seat, a slide valve vertically reciproeabie on said seat, to uncover and cover said port as the liquid rises and falls in the liquid-recovery chamber, the valve-engaging face of said seat being chrome plated, that part of said valve which engages sat seat being made of carbon and hav r-e' its engaging face lapped to glassdiite s:

17. In an air separator, an

'ery chamber. said wall ing chamber and a vented liquid-recovery 6118-111- her with a vent e interconnecting them near their upper ends, inlet and outlet conduits leading respectively to the upper part and from the lower part of the separating chamber, a conduit for carrying away excess liquids from the liquid-recovery chamber and terminating with a port opening through a wall of said liquid-recovhaving a finished face forming a valve seat, a slide valve reciprocable on said seat to cover and uncover said Port, a

stationary support connected to said wall and spaced from said valve, a coil spring acting between said support and valve to press the latter against its seat, and means for actuating said valve in response to the rise and fall of liquid in the liquid-recovery chamber.

14 controlling the outflow of liquid to said return conduit, means responsive to the rise or liquid in the liquid-recovery chamber above a predetermined level for opening said valve, said pump being located in the liquid-recovery chamber, and

mounted on a'wall of the liquid-recovery chamher, a drive shaft for the pump extending out of said liquid-recovery chamber through said wall, a seal for said shaft adjacent the outer portion of said wall, and a. drain conduit extending from the shaft at a point between the inner part of said wall and said seal downwardly into the liquid-recovery chamber.

- WARREN H. DE LANCEY.

REFERENCES crran The following references are of record in the file of this patent:

UNITED STATES PA'I'ENTS Number Name Date 976,917 Richards Nov. 29, 1910 2,032,886 Murphy et ai Mar. 3, 1936 2,090,035 Fellows Aug. 17, 1937 2,149,864 Osborne Mar. '7, 1939 2,184,133 Washlmark Dec. 19, 1939 1,0l4,178\ Roberts Jan. 9, 1912 1,091,238 Perkins Mar. 24, 1914 

